Internal-combustion engine



UNITED STATES PATENT OFFICE."

vrcron e. or'rnwnnn'or wrmow, umnnsorm.

INTERNAL-COMBUSTION ENGINE:

Specification of Letters fatent.

Patented Aug. 19, 1919.

f I I Application filed February 1, 1917. Serial.No. 146,010.

" To all wlw'm, it may concern:

Be it known that I, Vroron G. OTTEWELL,

a subject of the King of Great Britain, re-

siding at l/Vithrow, in the county of Wash-' ington and State of Minnesota, have 1n- The main object of the invention is toprovide an engine of this characterwith means whereby the shock produced by the violent explosion at the beginning of the power stroke of the engine is absorbed to relieve the working parts of the engine of excessive strains and the absorbed force imparted later on in the stroke thus producing a steady working pressure.

Another object is to provide an engine of this character. with means for evenly distributing the pressure during the power stroke of'the engine which also operates to almost completely exhaust the burned gases and produce" an even compression of the fresh charge thereby raising its temperature agndl permitting the use of a lower grade of Another object is to provide means for equalizing the pressure in the pressure controlled-means of all of the cylinders.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that' changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit ofthe invention.

In the accompanying drawings: Figure 1 represents a central vertical section through the upper portion of the engine cylinder equipped with this improvement.

' Fig. 2 is a side elevation of the upper portion of four engine cylinders shown provided with a means for equalizing the pressure in the pressure con-trolled means constituting the essential feature of this invention.

- ranged between it and said Walls.

Inthe embodiment illustrated, an engine cylinder 1 is shown having the'usual workmg plston 2 connected with the crank shaft (not shown) by the usual rod 3.

. This cylinder 1 has rigid head 4 secured to the cylinder walls by bolts in the ordlnary manner and having a gasket 5 ar- A solid core in the' form of a casting 6- is secured to the inner face of the head 4 and extends into the cylinder, being of less-diamet'er than said cylinder to provide a space between its outer side faces and the adjacent side walls of the cylinder in which the pressure controlled member 15, hereinafter described is designed to'operate. This casting 6 may be fixed to the engine head 4 by any suitable means, bolts 17 being here shown for this purpose. This casting has a'bore 8 extending longitudinally from end to end thereof which registers with an opening 9 formed in the head 4 of the cylinder and which latter is closed by a screw-threaded cap 10. An annular shoulder 11 is 'formed near the lower end of bore 8 of the casting '6 and is designed to'form a guide for hollow piston rod 12 which carries the pressure controlled member 15. The casting 6 is also provided with transversely extending passages 13 here shown arranged intermediately of the ends thereof, preferably nearer its lower end and which afl'ord communication between the bore 8 and thespace in the cylinder which surrounds said casting.

The cylinder 1 has a passage 14 opening through oneside wall near its upper end and which is designed to be connected with a pressure tank 50 for a purpose to be described.

The hollow piston rod 12 which carries the cup-shaped pressure controlled member 15, extends through the bottom of said member and has a flared head engaging a correspending shaped seat in said bottom and which is held in engagement therewith by a lock nut 16. This rod 12 is adapted to slide in the bore 8 carrying a piston 17 at its upper or inner end, said piston being shown threaded on said rod and clamped thereto by a lock nut 18. The inward movement of the piston rod 12 is limited by the engage ment of the piston 17 with the shoulder 11 at the lower end of'bore 8, an air cushion being formed in said bore between the piston 17 and said shoulder 11 when the mem-- her 15 moves inwardly thereby cushioning the movement of said member. The hollow rod 12 is provided in its outer end with a valve seat 19 with which is engaged a valve 20. This valve 20 has a. stem 21 extending upwardly into the rod 12 and which isulded in an adjustable nut.22, threaded 'in the upper end of said rod 12. A coiled. spring 23 is mounted on the stem 21 and forms a seat for said spring, the'tension of the spring being controlled by the adjust ment of the nut 22 on the'rod 12, or a pin 24 may be made adiustaibl'e if desired and the same be accomp ished. This spring 23 operates to normally hold the valve 2? closed, but will yield sufiiciontly to permlt said valve to open when the pressure in the explosion chamber E exceeds the resisting permit the passage of gases contained in said member up between said casting and member into the space which surrounds the casting adjacent the head of the cylinder. It will thus be seen that communication is afiorded between the bore 8 and the space surrounding the casting, and with the interior of the cup-shaped member '15 by means of the transverse passages 13, the apertures 25 in thehollow piston rod 12 operating to bring the interior of member 15 into communication with the explosion chamber E when the valve 20 is lifted, which will occur under conditions presently to be described.

. This cu1shaped member 15, Which may be termed a yieldable cylinder head or auxiliary piston, and the parts cooperating therewith, are here shown in connection with a. single cylinder only, but it is to ,be

understood that it may be used in an engine having any desirednumber of cylinders, four of such cylinders being shown in -l'Vhcn more than one cylinder is em- Fig. 2. ployed, it is found desirable to have the pressure 1n the member 15 and the space surrounding the casting 6 of the different cylinders equal, as some difficulty might be experienced in adjusting the individual valYcs 20 to produce this effect and consequcntly the pressure tank 50 is provided with pipes 51 leading therefrom and connecting with the passages 14 of the cyllnders and the air supplied from this tank merely operates to equalize the pressure in all of the cylinders at the time the auxiliary pistons 15are at their lowest points of travel. This-pressure tank 50' is provided wlth a .pipes 14 to this space and thereby equalizes thepressure in all of the cylinders. It is not intended that this tank be provided with any outside source of pressure, though it might be deslrable under some condltlons, as

for instance, in starting the engine when. the

pressure in tank 50.and that above the pistons 15-had-been reduced to such a low point as to render the starting of the engine diflicult because of the low compression in the combustion chamber E. A p

In the use of an engine equipped with this improvement, assuming the space Within the member 15 and around the casting 6 to have a pressure of sixty pounds. This pressure will operate to hold the auxiliary piston 15 down at the extreme limit of its inward stroke which is controlled by the engagement of the piston 17 on the rod 12 with the shoulder 11. When in this position with the .pressure above described, the working piston 2 will be at the beginning of its compression stroke, and as said piston advances, and the pressure of the 'fresh charge in the chamber E increases beyond sixty pounds, it will operate to lift the auxiliary piston 15 until the piston 2 reaches the limit of its compressing stroke and then the compression in chamber E will be about equal to that within the piston 15 and in the space above it. The spring 23 operates during this time to hold the valve 20 on its seat 19 in the hollow piston rod 12 and when the explosion occurs in the explosion chamber E.. the force exerted thereby overcomes the pressure of spring 23 and the pressure in piston 15 and opens the valve 20, thereby admitting-the compressed air from the eX- plosion chamber E into the cup-shaped member 15, said air passing in through the hollow piston 12 and out through the apertures 25 therein."- At the same time the auxiliary piston 15 is forced upwardly or outwardly. The admission of the compressed gases through the hollow rod 12 continues at each power stroke until the pressure within the auxiliary piston and the space above it, together with the strength of the spring 23 is suflicient to hold the valve 20 seated by means of thenut 22.'al so by theexposure of the'outer face of the valve 20, the exposed face of said valve-within the hollow piston rod. being greater than that which is exposed to the explosion chamber E;

When the auxiliary piston 15 is forced upwardly by the explosion in chamber E it 5 raises the pressure within the piston 15. and

. the space above it and relievesthe pressure in the explosion chamber, until the two pressures become equal. The working piston 2 moving outward, relieves the pressure in the explosion chamber E and the pressure within the member '15 causes it to move inward thereby keeping the pressure within the explosion chamber even. Hence it will'be seen that the force exerted on the piston 2 is relie'ved; at the first part of the explosion stroke and added later on in the stroke, thus giving a steady working pressure instead of a shock such as usually occurs v When the piston 2 reaches the point at .20 which the exhaust port opens, the auxiliary piston 15 should have reached its llmlt of inward movement and is brought gradually to rest by the air cushion formedin the space between the shoulder 11- and the piston 17,

the air forming said cushion being supplied through.t he transverse passages. 13. The

pressure within and above the piston '15 holds said piston in inward position during the exhaust stroke of piston 2, the two p15- tons 2 and 15 being then in close proximity with the space between them reduced to a minimum, so that all of the burned gases in said space will be almost if not completely exhausted. This is very desirable as the fresh charge which is drawn in by piston 2 diluted withon its next stroke will not any burned gases.

When the pressure tank 50 is employed in connection with two pr more cylinders of an 40 engine as is shown In Flg. 2, the par passages. or pipes 51 thereof communicate with the cylinders through their passages 14 and these passages are open only when the pistons 15 of the respective cylinders are below said openings 14, and when they are at this point, the pressure from the tank is admitted to the space above said pistons 15 or vice versa. This does not cause any loss of pressure obtained by the ex losion which 50 forces the piston 15 outward butmerely equalizes the pressure in all of the cylinders at the time when the pistons 15 are at their lowest point of travel.

In the embodiment herein shown, no intake .525 or exhaust valves or spark plugs are shown,

as they form no part of the invention, and

as'they are so well known in the art, illustration thereof is not deemed necessary.

From the foregoing description, taken in 0 connection with the accompanying drawing,

the advantages of. the construction and of the method of operation will be readily apparent to those skilled in'the art to which the invention appertains and while I have 6-5 described the principle of operation of the invention together with the device which I now. onsider to be the best embodiment thereof -I desire to. have it understood that the device shown'is merely illustrative and 4 that such changes may be made as are within the scope of the claimed invention.

cla1m: x 1.' In an lnternal combustion engine, a cylinder provided with a head and having a working and an auxiliary piston and with a combustion chamber between them, said auxv iliary piston having an opening communicatmg with the combustion chamber of the cylinder, a valve normally closing said. opening,

and pressure means for holding said valve closed, the pressure of said holding means being overcome by the pressure produced by the explosion in the combustion chamber of the cylinder wherebg said valve is opened and the pressure me ium .in the combustion chamber .admitted to. said auxiliary piston thereby relieving the pressure on the working piston, the pressure medium in said auxiliary piston operating to advance the piston while the working piston is moving outward.

2. In I an internal combustion engine, a

cylinder having two pistons movable toward and away from each other, one of-s'a'id pistons being pressure controlled and having means for retaining the pressure behind it whereby it is held in advanced position,

said retainingmeans being opened on the reaching of a predetermined pressure in the space between said pistons, whereby sald pressure controlled piston is moved backward and additional pressure fluid admitted into and behind said iston until the pressures behind and .in at vance thereof become equal, the pressure behind said pressure controlled piston operating to move it forward ioo on the forward movement of the other piston.

3. In an internal combustion engine, a cylinder having two pistons movable toward and away from each other, one of said pistons being pressure-controlled and having a pressure fluid within and behind it for normally holding the piston at the limit of its inward. stroke, said piston having an opening in its inner end, a spring pressed for said rod, said rod having apertures to afford communication with the interior thereof and with the interior of said piston, and means for guiding said piston.

5. In an internal combustion en ine, a cylinder provided with a headand Iiaving a working and an auxiliary piston, said auxiliary piston. being pressure controlled and cup-shaped with its closed end extending inward, and its open end positioned toward the head of the cylinder, a core carried by the said engine head and extending into said auxiliary piston with itssides spaced from the side walls of the piston, and cooperating means carried b said piston and core for limiting the inward movement of the piston. I

6. In an internal combustion engine, a

cylinder provided with a head and having a working and an auxiliary piston, said auxiliary piston being pressure controlled.

, and cup-shaped with its closed end extending. inward, and its open end positioned toward the head of the cylinder, a core carried by said engine head and extending into said auxiliary piston with its sides spaced from the side walls of the piston, said core having a bore extending longitu dinally therethrough, a piston operating in said bore, means in said bore for limiting the movement of said piston, and a connection between said bore piston and said auxiliary piston whereby the latter is limited in its inward movement by the'limiting means for said bore piston.

7. In an internal combustion engine, a cylinder provided with a head and having a working and an auxiliary piston, said auxiliary piston being pressure controlled and cup-shaped with its closed end extending inward, and its open end positioned toward the head of the cylinder, a core carried by the said engine head and extending into said auxiliary piston with its sides mismaspaced from the side walls of the piston, said core having a'bore extending longltudinally therethrough, a piston operatlng in said bore, means in said bore for limiting the movement of said piston, and a connection between said bore piston and saidiauxiliary piston whereby the latter is limited in its inward movement by the limiting means for said bore piston, said core having air passages communicating with said bore to admit air for cushioning the inward movement of the piston.

8. In an internal combustion en he a' cylinder provided with a head and having a working and an auxiliary piston, said auxiliary piston having ameans whereby it is retracted. at the beginning of the power stroke of the working piston and advanced during the outward movement of said working piston thereby evenly distributing throughout the power stroke the pressure of the gases produced by the explosion before the beginning of said stroke, and means for cushioning the inward movement of said auxiliary piston.

9. In an internal combustion engine, a cylinder provided with a head and having aworking and an auxiliary piston, said aux-.

iliary piston having a meanswhereby it is retracted at the beginning of the power stroke of the working piston and advanced during the outwa'rd movement of said working piston thereby evenly distributing throughout the power stroke the pressure of the gases produced by the explosion before the beginning of said stroke, and means for providing an air cushion to limit the inward movement of said auxiliary piston.

In testimony whereof I afix my signature in presence of two witnesses. 5

VICTOR G. OTTEWELL. Witnesses E. W. REDMAN, ROBERT A. BATES. 

